The invention concerns the production of quinoline compounds containing sulfonic acid groups, said quinoline compounds and the conversion thereof into dyes containing sulfonic acid groups. The dyes according to the invention can be used especially to label analytes and for example to label biomolecules.
Dyes from the class of coumarin, xanthene and oxazine dyes and related derivatives are preferably used as labelling groups in chemical, biological and medical analytics due to their very good spectral properties and in particular their fluorescence. (J. Slavik, Fluorescent probes in Cellular and Molecular Biology, CRC Press, Boca Raton, Ann Arbor, London, Tokyo, 1994). A large number of long wavelength xanthene dyes (rhodamines etc.) are described in EP 0567622 B1. Labelling dyes from the oxazine class are disclosed in EP 0747447 B1. Sulfonic acid derivatives of xanthene dyes are described in WO 99/15517. Dyes from the carbopyronine and amidopyrylium dye classes are described in WO 00/64986 and WO 00/64987. In this connection dyes having a high fluorescence quantum yield play an important role since the fluorescence enables a very sensitive detection of the labelled analyte. However, non-fluorescent derivatives are becoming increasingly important as quenchers in special methods.
A good solubility e.g. in aqueous systems is necessary in addition to a simple and reliable detectability for an application as labelling groups for analytes. In other cases exactly the opposite is desired i.e. a good solubility in an unpolar environment e.g. cell membranes.
Hence, depending on the concrete conditions, certain specific properties which the fluorophore should have in addition to its optical properties are of decisive importance for an application as a labelling group for analytes or in similar methods. In the case of the dyes of the said patents, these properties can either not be achieved or, if at all, only in a very complicated manner by dye synthesis using appropriate educts.